Fire fighting in close quarters buildings such as in residential homes and apartments often result in heavy water damage. The reason is that use of standard fire fighting equipment usually results in the discharge large volumes of water into the homes and apartments. These volumes are usually greatly in excess of that needed to extinguish the fire. Chemical fire extinguishers are useful for putting out small fires but are not much use against larger fires.
It is known that high pressure water mist can absorb heat at very high rates due to the large surface area of very many very small droplets. The creation of very small droplets in the range of 50 to 100 microns was found by Marioff Corporation tests to increase vaporization rates by as much as 400 times the rates of conventional sprinkler drops. However, when fighting fire in close quarters the water mist must be delivered at distances of many feet and at high rates. Also, firefighters need to be able to carry such devices up several floors and use such devices single handedly.
Fire fighting using high velocity water turbine driven fans has been in use for number of years. U.S. Pat. Nos. 5,013,214 and 5,125,797 were issued to Applicant. These fans have been utilized mostly in de-smoking operations and were sometimes equipped with liquid spray nozzles for fire fighting. Because of relatively large turbine water flow rate, spray nozzles could utilize only a small fraction of water supplied to the turbine. Thus, two large supply and drain hoses were required to carry water flows of 50 to 60 gallons per minute to and from the fire. The weight of those fans was around 40 pounds and the fire fighter also needed to carry two heavy fire hoses.
Applicant was granted on Jul. 20, 1999 a patent (U.S. Pat. No. 5,924,286) on a very high speed, high efficiency very compact radial inflow hydraulic turbine. More specifically Applicant was granted on May 12, 2009 a patent for a high-velocity water misting gun capable of fighting a fire having approximately 2 MW of heat content. This patent is U.S. Pat. No. 7,530,553. Since its application date of May 8, 2006 further research in fighting larger “flash over” type fires has shown the need to increase the water misting gun fire fighting capacity up to 10 MW heat content. In order to effectively fight such fires from various distances, it is desirable to have water mist effective range and mist cone angle adjustable by varying air jet velocity, air mass flow rate and water mass flow rate adjustable independently from each other.
What is needed is a fire fighting device that can be used effectively in fighting larger flash over type fires with maximum protection of the fire fighting personnel.